Stocks showed modest gains at midday Friday, as they recovered a bit from Thursday's broad sell-off, but still were on pace to close lower for the week. The Nasdaq rose 0.6%, while the Dow Jones industrial average and S&P 500 both tacked on 0.4%. Volume was tracking down from Thursday's levels on both main exchanges. For the week, the Nasdaq is on track to post a 0.1% loss. The S&P 500 is on pace to end 1% lower, and the Dow is set to lose 1.2%.